Prenatal Testing and Screening Guide for Expectant Moms

Prenatal testing and screening are vital during pregnancy to ensure that both mom and baby are progressing through the pregnancy as expected.  There are a host of prenatal screening and diagnostic tests, each designed to measure or evaluate a specific aspect of the mother or baby’s progress.

WHAT IS PRENATAL TESTING AND SCREENING?

Screening tests show the chance or odds of a developing baby to have a certain genetic condition, such as spina bifida or Down syndrome, whereas diagnostic tests are more accurate and indicate whether the developing baby actually has a certain genetic condition.

Our prenatal counseling is specifically designed to provide early screening for both mother and baby.  It’s important that your health and wellness be managed during your pregnancy, and that all relevant prenatal screens and tests be completed at the appropriate stage of pregnancy.

WHEN SHOULD I TALK WITH A GENETIC COUNSELOR?

Genetic counseling is intended to help expectant mothers that fit one of any of the following categories:

• Women over the age of 35 at the time of delivery.
• Women that have had abnormal screening or testing results during pregnancy.
• Women who have had certain ultrasound findings detected during pregnancy.
• Couples with concerns of a condition in their family history.
• Couples with a history of complications or abnormalities in a previous pregnancy.
• Couples who have experienced pregnancy losses or a stillbirth.
• Women taking certain medications in pregnancy.

WHAT MIGHT I LEARN DURING GENETIC COUNSELING?

Genetic counseling is an important part of your care.  The process allows your doctor to identify particular risk factors as well as any birth defects or genetic conditions that are developing during pregnancy.

WHAT PRENATAL TESTS ARE PERFORMED IN THE FIRST TRIMESTER?

• Sequential screening, done from the maternal blood, begins between 11 to 14 weeks and includes a special ultrasound measurement, called a nuchal translucency, on the fetus.  The second part of sequential screening is completed in the second trimester.
• Cell-free DNA screening can be completed as early as 10 weeks of pregnancy and up through the second trimester.
• Chorionic villus sampling is a diagnostic test which is offered in certain pregnancies between 11 and 14 weeks.

WHAT PRENATAL TESTS ARE PERFORMED IN THE SECOND TRIMESTER?

• Quad and penta screens are done on maternal blood and can be completed between 15 to 21 weeks of pregnancy.
• Amniocentesis, which is a diagnostic test, can be completed between 15 to 21 weeks of pregnancy.

WHAT PRENATAL TESTS ARE PERFORMED IN THE THIRD TRIMESTER?

• Rarely is genetic testing performed in the third trimester; however, cell-free DNA screening and amniocentesis would both be options, if indicated.